Plate side trimming shear



Sept. 30, 1969 D. HOBSON ETAL 3,469,483

PLATE SIDE TRIMMING SHEAR Filed Oct. 4, 1966 4 Sheets-Sheet 1 INVENTORSI DAVID HOBSON a DEREK HATTERSLEY b 6% :4 9 Q THEIRATTORNEY Sept. 30,1969 p. HOBSON ETAL 3,469,483

' PLATE SIDE 'rnmmms smzma Filed Oct. 4, 1966 4 Sheets-Sheet 2 VHF-JF/GiZ.

INVENTORS DAVID HOBSON & BY DEREK HATTERSLEY TH i ATTORNEY Sept. 30,1969 o. HOBSON ETAL 3,469,483

PLATE SIDE TRIMMING SHEAR Filed Oct. 4, 1966 4 Sheets-Sheet 5 INVENTORSDAVID HOBSON & BY DEREK HATTERSLEY T EIR ATTORNEY Sept. 30,- 1969 ogsoflETAL 3,469,483

PLATE sum TRIMMING snmry Filed Oct. 4, 1966 4 Sheets-Sheet 4.

INVENTORS DA/ID HOBSON & BY DEREK HATTERS LEY United States Patent U.S.Cl. 83-216 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates toa shear of the type used to side trim metallic plate. The shearcomprises a pair of blade holders, each having a cooperative blade. Theupper blade holder is reciprocated towards and away from the other bladeholder, which is stationarily mounted. The upper blade holder is carriedin a pivotal guide to which there is connected a backing-off device. Thebacking-01f device is made up of a first link having one end pivotallyconnected to the guide and the other end to a second link, which ispivotally carried by the shear frame. A connecting rod is also provided,which is connected to the links and the main drive of the shear.

This invention relates to opposed side trim shears. With such shears,where the opposite sides of a plate are to be cut simultaneously, it isnecessary to draw the blades of the shears away from the cut edges ofthe plate on the return stroke of the shear. This is referred to asbacking-01f of the blades.

The present invention provides a shear having a pair of blade holdersadapted to carry a pair of cooperating blades, drive means forreciprocating a first of the blade holders towards and away from theother blade holder in a pivotally mounted guide to effect a shear, and abacking-01f device, the backing-off device comprising a substantiallyhorizontal linkage pivotally coupled between the guide and a part of theshear frame and having an intermediate pivot point, and mechanical meansfor pivoting the linkage at its intermediate point at the end of thecutting stroke. The horizontal linkage is held in a fixed positionduring the cutting stroke of the shear. By this means, during thecutting stroke the movable blade travels in a perfectly straightvertical line, and when the linkage pivots at the end of the cuttingstroke the withdrawal away from he plate is rapid.

Preferably the backing-off device comprises a linkage including a firstsubstantially horizontal link having one end pivotally coupled to theguide and the other end pivotally coupled to one end of a secondsubstantially horizontal link which has its other end pivotally coupledto the shear frame, and means coupled between the blade drive and thepivot between the links, movable relative to the links during thecutting stroke and arranged to engage the links at the end of thecutting stroke to displace the centre pivot point.

Preferably the pivotal coupling between the end of the linkage and theshear mounting is adjustable in order to adjust the separation of theblades of the shear. In one form the end of the linkage is mountedeccentrically on a shaft and the shaft is arranged to be drivenautomatically by a motor to assume a position corresponding to apredetermined blade separation.

Material to be cut is preferably fed to the pair of opposed side shearson an entry roller table and removed from the shears on an exit rolltable. Another aspect of the invention provides that the entry and exitroller tables are line shaft driven, the entry table having an automaticcontrol for the drive to meter material into the shear.

The exit roller table has a separate control motor, but the entry andexit roller tables can be connected together during cutting.

One embodiment of opposed side trim shear arrangement, in accordancewith the invention, will now be described, by way of example only, withreference to the accompanying drawings of which:

FIGURE 1 is a plan view of an opposed side trim shear arrangement,

hFIGURE 2 is a front view partly in section of one s ear,

FIGURE 3 is a side view of the shear in FIGURE 2,

FIGURE 4 is a sectional view on the line IV-IV of FIGURE 2.

The shear arrangement shown in FIGURE 1 includes two opposed side trimshears, one 12 being a fixed shear and the other 13 being arranged tomove towards or away from the fixed shear to accommodate differentwidths of plate. An exit roll table 14 has a plurality of rollers 15driven by a line shaft drive arrangement from a common motor 1-6. Amoving longitudinal side guide 17 is driven through shafts 18 and gearboxes 20 by a motor 19. The movable shear 13 is also driven by motor 19,and since the other end of the side guide 17 is fixed to the shaft 13,the side guide 17 always remains parallel to a fixed side guide 17A atthe other side of table 14.

An entry roller table 21 comprises a plurality of rollers 22 each driventhrough a line shaft 23 from a common motor 24. Motors 16 and 24 may beconnected as shown. A longitudinal travelling magnet 25 is driven from amotor 24A, which when desired may be synchronised with motor 24 throughshafts 26, this then synchronises the travelling magnet with the entryroller table. Cross travel magnets 27 are employed on the entry rollertable to line up the plate prior to shearing. A centre support table 28is provided bridging the entry and exit roller tables, this table alsobeing driven by the motor 19 and arranged always to be midway betweenthe shears 12 and 13. A scrap conveyor 30 is provided for removing thescrap from beneath the shears. Separate automatic controls are providedfor the motors 16 and 24 so that the entry and exit tables may be drivenindependently. The moving shear 13, shown in detail in FIGURES 2, 3, and4, comprises a main shear frame 31 mounted on slides 32 fastened tobeams 33 for sliding movement towards and away from the fixed shear. Theshear is driven from the motor 19 through screws 33A. The frame 31carries a fixed lower blade 34 and an upper blade 35 carried in a bladeholder 36 mounted in a guide 37 for vertical sliding movement relativethereto. The guide 37 has an integral pin 38 either side carried in theframe 31 so that the guide carrying the blade holder and blade can pivotabout the horizontal axis 40 of the pin, parallel to the movement ofmaterial through the shear. Gags 41 are mounted on the frame to clampmaterial to be cut between the gags and the lower blade 34.

A motor 42 is mounted on the frame 31 and connected through a brake andcoupling 43 to a worm 44 engaging a worm wheel 45 keyed on a crank shaft46 rotatably mounted in bearings 47 in the frame 31 for rotation aboutits horizontal axis 48 parallel to the axis 40. The centre part 50 ofthe shaft 46 has its axis 51 displaced from the axis of rotation of theshaft and carries on bearings 52a double connecting rod 53 integral atits lower end 54. The lower end 54 is seated in a pitman bearing 55 atthe top of the blade holder 36, and is held in the seating 55 by a tie56. It will be seen that rotation of the shaft 46 reciprocates the bladeholder 36 carrying the upper blade 35 up and down by means of theeccentrically mounted connecting rod 53, the blade holder 36 sliding inthe guide 37. A balance cylinder 56A is used to take the weight of theblade holder 36.

On each side of the shear is located a mechanical backing-off device inthe form of a toggle mechanism, only one of which will be described,best seen in FIGURE 3. A horizontal link 57 has one end 58 connected tothe guide 37 for pivotal movement about a horizontal axis 60, and hasits other end 61 pivotally mounted on a pin 62 having a horizontal axis63; a second horizontal link 64 has one end 65 pivotally carried on thepin 62 and its other end 66 pivotally mounted on a pin 67 having ahorizontal axis 68, the pin 67 being an eccentric on the end of a shaftmounted for rotation in the frame 31. By shifting the position of axis68, the horizontal separation of blades 34 and 35 can be adjusted. Amotor is coupled to the shaft carrying the pin 67 to automatically fitthe eccentric to a position corresponding to a predetermined bladeseparation. Also coupled to the pin 62 is a toggle 70 carried on thepiston rod 71 of a cylinder 72 pivotally mounted on a pin 73 fixed tothe frame 31. The piston and cylinder assembly 72 is pressurised toapply a downward bias to the links 57 and 64, maintaining them in theirsubstantially horizontal position by means of a stop 69 under the toggle70. The piston rod 71 passes through a clearance hole in the stop 69,which is fixed to the frame 31. A link 74 has its upper end 75 pivotallymounted on a pin 76 eccentrically carried on the end of the crank shaft46, and its lower end 77 is formed with a slot 78 in which the pin 62 isreceived. The slot 78 is arranged so that during the downward stroke ofthe blade the link 74 moves in such a way that no force is exerted onthe pin 62 and therefore there is no movement of the links 57 and 64. Atthe end of the cutting stroke the bottom end 80 of the slot 78 contactsthe bottom of the pin 62. On further rotation of the shaft 46, the link74 lifts the pin 62 against the pressure of the cylinder 72, therebycausing the links 57 and 64 to pivot. Since the end 66 of link 64 isfixed, the end 58 of link 57 is drawn towards the shear, thus pullingthe lower end of the guide towards the frame 31. Since the guide 37 ispivoted at axis 40, the guide 37 rotates, and the blade 35 carried inthe blade holder 36 is drawn away from the sheared edge; thisbacking-off of the blade away from the sheared edge being extremelyrapid.

On further rotation of the shaft 46, the pin 62 reaches the top of itslift,-and thereafter the pin 62 is returned to its original position bythe cylinder 72 being controlled by link 74. When the toggle 70 islowered on to the stop 69, the links 57 and 64 are again substantiallystraight, and the cutting stroke then begins.

A heel blade 81 cuts each sheared piece of plate off, and allows thescrap to fall onto the conveyor 30.

In accordance with the provisions of the patent statutes, we haveexplained the principle and operation of our invention and haveillustrated and described what we consider to represent the bestembodiment thereof. However, we desire to have it understod that withinthe scope of the appended claims, the invention may be practicedotherwise than as specifically illustrated and described.

What is claimed is:

1. A shear including a frame and a pair of blade holders adapted tocarry a pair of cooperating blades,

a guide for receiving a first blade holder in a manner to permitrelative movement therebetween,

means supported by said frame for carrying said guide in a manner torestrict movement of the guide to only a pivotal movement and in adirection towards and away from the sheared edge of the material,

drive means for reciprocating said first blade holder towards and awayfrom the other blade holder to effect a shear,

a backing-off device comprising a substantial linkage pivotally coupledbetween the guide and a part of the shear frame and having anintermediate pivot point, and

mechanical means for pivoting the linkage at its intermediate point atthe end of the shearing stroke.

2. A shear having a frame which receives a pair of blade holders adaptedto carry a pair of cooperating blades;

a drive means for reciprocating a first of the blade holder towards andaway from the other blade holder in a pivotally mounted guide to effecta shear;

a backing-off device comprising a substantially horizontal linkagepivotally coupled between the guide and a part of the shear frame andhaving an intermediate pivot point; and

mechanical means including a further link coupled between the linkageand the drive means and arranged to move freely relative to the linkageduring the cutting stroke and to engage the linkage in the end of thecutting stroke to displace the intermediate pivot point.

3. A shear according to claim 2 in which the further link is connectedto the linkage by a pin and slot coupling.

4. A shear according to claim 2 in which the drive means includes ashaft to which the first blade holder is eccentrically connected, andthe further link is also eccentrically connected to the shaft.

5. A shear according claim 2 including retaining means for holding thelinkage horizontal during the cutting stroke.

6. A shear according to claim 5 in which the retaining means arehydraulic and act, in the opposite direction to the action of themechanical means on the linkage to urge the intermediate point of thelinkage against astop.

7. A shear according to claim 2 in which the linkage is arranged tomaintain a blade in the first blade holder substantially vertical duringthe whole cutting stroke.

8. A shear according to claim 2 in which the pivotal coupling betweenthe linkage and the part of the shear frame is adjustable to vary thehorizontal separation of the shear blades.

9. A shear according to claim 8 in which the end of the linkage coupledto the shear frame part is eccentrically mounted on a shaft arranged tobe driven automatically to assume a position corresponding to apredetermined blade separation.

10. A pair of side trimming shears according to claim 2 in combinationwith line shaft driven entry and exit roller tables, the entry tablehaving an automatic control for the drive to meter material into theshear.

References Cited UNITED STATES PATENTS 3,154,988 11/1964 Gries 83-558 X3,246,552 4/1966 Sieger 83-556 X 3,263,546 8/1966 Musly et a] 83556WILLIAM S. LAWSON, Primary Examiner U.S. Cl. X.R. 83-556

